This invention is related to the field of trigger dispensers, also known as trigger sprayers. The invention is particularly directed to a trigger sprayer having a housing with numerous features integrally molded therein including a shroud having sides which extend rearward to an integral ergonomic saddle having a surface configured to rest upon the user's hand during trigger sprayer actuation.
There are numerous patents that have issued on trigger dispensers of the general type to which this invention relates. The patents discussed below exemplify such prior art trigger dispenser patents. Generally, a trigger dispenser of the type involved here is a relatively low cost pump device which may be grasped in the hand and has a pump chamber which is operable by pulling a trigger to pump liquid from a container and through a nozzle at the front of the dispenser.
Such trigger dispensers may have a variety of features that have become common and well known in the industry. For example, the dispenser may have a vent system to prevent a vacuum from developing in the container as liquid is removed therefrom. If no vent system is included, the vacuum eventually prevents the trigger dispenser from pumping the liquid from the container. Many of these vent systems are connected to the trigger such that as the trigger is actuated, the vent is repeatedly opened and closed at appropriate points in the pumping cycle to relieve the vacuum.
U.S. Pat. Nos. 3,840,157 and 5,222,637 disclose trigger dispensers having ergonomic saddles with surfaces configured to rest upon the user's hand during trigger sprayer actuation. However, the particular configurations do not employ shrouds, thus making the functional structures of the trigger dispensers visible to the user. A smoother, more streamlined configuration is more aesthetically desirable. As a result, shrouds are typically used to give the housing a more streamlined appearance.
U.S. Pat. No. 4,958,754 discloses a trigger dispenser which has a housing with an integrally molded shroud. This shroud makes the housing more streamlined and appealing. The shroud is integrally molded with the housing to reduce assembly costs by eliminating a separate component. The shroud includes a saddle which rests on the user's hand during use to aid the user in grasping the dispenser. However, molding constraints require that the bottom of saddles of this type be open, and therefore a surface is not provided on the saddle to rest upon the user's hand during trigger sprayer actuation. Rather, the edges of the saddle surrounding the opening rest upon the user's hand. When a load is distributed over a relatively small area, the stress associated with that load is increased. In this instance since the stress is in the user's hand, the user's comfort level is reduced by a reduction in loaded area. Thus, while sprayers of this type provide an aesthetic housing with numerous advantages, the level of comfort is less than optimal.
U.S. Pat. No. 5,228,602 discloses yet another trigger dispenser which is partially shrouded. The forward section of this dispenser is shrouded so as to provide a streamlined appearance. Depending from the rearward side of the shroud is a band which forms an ergonomic saddle. Although this saddle has a surface to rest upon the user's hand during trigger sprayer actuation, the overall appearance of the housing is not streamlined because the sides of the shroud do not extend rearward over the saddle. Thus, as with the aforementioned patents, this patent does not solve the problem of providing a one-piece shrouded housing with a totally streamlined appearance and an ergonomic saddle with a surface configured to rest upon the user's hand.
Part of the difficulty in producing a housing having an integral shroud with a totally streamlined appearance as well as a surface to rest upon the user's hand is the constraints of plastic molding. Plastic parts must be molded with relatively thin cross-sections to prevent unsightly shrinkage voids. Thus, plastic parts are frequently made hollow to keep the cross-sectional thicknesses thin. However, a hollow cannot be created within a trigger dispenser housing without leaving an opening somewhere in the housing for the mold to withdraw from the hollow. If the opening is put in the housing at the bottom of the saddle, then the saddle surface is broken by the opening. As a result, the edges of the opening rest upon the user's hand and cause a reduction in comfort. Alternatively, the opening may be placed at the top or at the side but this reduces the aesthetic appeal of the trigger dispenser which is the purpose of the shroud in the first place. Thus, in the prior art where a surface for the user's hand has been provided in the saddle, aesthetics have been sacrificed, and where aesthetics have not been sacrificed, a surface for the hand has not been provided.
The present invention overcomes these disadvantages of the prior art trigger dispensers and provides a unique trigger dispenser having a housing with an integral shroud which has a totally streamlined appearance and a surface to rest upon the user's hand during the trigger dispenser actuation.